\begin{tikzpicture}[>=Stealth,
    every node/.style={fill=white, inner sep=1pt},
]
    \pgfmathsetmacro{\factorx}{0.25}
    \pgfmathsetmacro{\factory}{0.25}
    \draw [->] (0, 0) -- (8.6, 0) node[below=0.1] {时间(日)};
    \draw [->] (0, 0) -- (0, 3.8) node[left=0.2em] {温度(℃)};
    \draw (0, 0) coordinate(O) node [below left] {\small $0$};
    \foreach \x in {2, 4, ..., 30} {
        \draw (\factorx * \x, 0) -- (\factorx * \x, -0.15) node [below] {\small $\x$};
    }
    \foreach \y [count=\i] in {8, 10, ..., 18} {
        \draw (0, \factory * \y - \factory * 6) -- (-0.15, \factory * \i * 2) node[left] {\small $\y$};
    }

    \draw plot coordinates{
        %            x               y
        (\factorx *  1, \factory *  12.2 - \factory * 6)
        (\factorx *  2, \factory *  13.0 - \factory * 6)
        (\factorx *  3, \factory *  16.0 - \factory * 6)
        (\factorx *  4, \factory *  13.0 - \factory * 6)
        (\factorx *  5, \factory *  13.8 - \factory * 6)
        (\factorx *  6, \factory *   8.8 - \factory * 6)
        (\factorx *  7, \factory *   9.0 - \factory * 6)
        (\factorx *  8, \factory *   9.2 - \factory * 6)
        (\factorx *  9, \factory *  10.0 - \factory * 6)
        (\factorx * 10, \factory *  15.8 - \factory * 6)
        (\factorx * 11, \factory *  15.0 - \factory * 6)
        (\factorx * 12, \factory *  17.0 - \factory * 6)
        (\factorx * 13, \factory *   9.2 - \factory * 6)
        (\factorx * 14, \factory *  10.0 - \factory * 6)
        (\factorx * 15, \factory *  11.5 - \factory * 6)
        (\factorx * 16, \factory *  12.0 - \factory * 6)
        (\factorx * 17, \factory *  12.8 - \factory * 6)
        (\factorx * 18, \factory *  13.8 - \factory * 6)
        (\factorx * 19, \factory *  15.0 - \factory * 6)
        (\factorx * 20, \factory *  16.2 - \factory * 6)
        (\factorx * 21, \factory *  15.8 - \factory * 6)
        (\factorx * 22, \factory *  15.0 - \factory * 6)
        (\factorx * 23, \factory *  11.0 - \factory * 6)
        (\factorx * 24, \factory *  13.0 - \factory * 6)
        (\factorx * 25, \factory *  17.0 - \factory * 6)
        (\factorx * 26, \factory *  15.0 - \factory * 6)
        (\factorx * 27, \factory *  13.0 - \factory * 6)
        (\factorx * 28, \factory *  11.0 - \factory * 6)
        (\factorx * 29, \factory *  14.5 - \factory * 6)
        (\factorx * 30, \factory *  14.0 - \factory * 6)
    };
\end{tikzpicture}

